@article{JMPA_1838_1_3__10_0,
     author = {Chasles, M.},
     title = {D\'emonstration g\'eom\'etrique de la formule int\'egrale $\int^b_o\int^c_b\frac{\left(v^2-\varsigma^2\right)dv.d\varsigma}{\sqrt{\left(v^2-b^2\right)\left(c^2-v^2\right)\left(b^2- \varsigma^2\right)\left(c^2-\varsigma^2\right)}}=\frac{1}{2}\pi$},
     journal = {Journal de Math\'ematiques Pures et Appliqu\'ees},
     pages = {10--16},
     publisher = {Gauthier-Villars},
     volume = {1e s{\'e}rie, 3},
     year = {1838},
     language = {fr},
     url = {http://www.numdam.org/item/JMPA_1838_1_3__10_0/}
}